Changeset 11904

From Sukender, "As discussed in osg-users, I found output directories with CMake >= 2.8.1 are wrong under MSVC (As Chuck said, it's to be related to CMake, and not MSVC).

But I also found rev. 11354 (from Wang Rui) added a change in OsgMacroUtils? which adresses a similar issue: Wang told the "../../bin" prefix wasn't working. However I think the fix isn't correct because it checks the MSVC version instead of the CMake version. Here is my fix, against latest trunk (root CMakeLists.txt, and CMakeModules/OsgMacroUtils.cmake).